1. Field of the Invention
The present invention relates to a compact size combustion engine for use in a brush cutter or a hedge trimmer.
2. Description of the Prior Art
In this kind of combustion engine, a priming pump 42 is generally secured to a lower portion of a carburetor 41 that protrudes laterally outwardly of an engine body 1 as shown in FIG. 4. The carburetor 41 used therein is of, for example, a diaphragm type that is operable in such a manner that when the priming pump 42 is driven, a quantity of fuel can be drawn into a metering chamber (not shown) defined in the carburetor 41. In such case, the priming pump 42 is positioned in a deep inner region beneath the carburetor 41 as clearly shown in FIG. 5, and accordingly, the presence of fuel tubes 43 and 44 nearby interfere often the manipulability of the carburetor 41.
Also, the Japanese Laid-open Patent Publication No. H10-311227, published Nov. 24, 1998, discloses the priming pump mounted on a projection formed in an insulator structure interposed between the carburetor and the engine body. It has, however, been found that the provision of the insulator structure results in a considerable increase of the size. In addition, the engine system in which the priming pump is secured to an air cleaner housing is also known in the art. However, since the air cleaner housing is generally low in strength, difficulty has been often experienced in applying a relatively high pressing force to the priming pump for manipulation.